Re: [PATCH v8 08/10] cpufreq: dt: Validate all interconnect paths

Matthias Kaehlcke
2020-05-12T21:47:58Z

Hi Georgi,

On Tue, May 12, 2020 at 03:53:25PM +0300, Georgi Djakov wrote:
> Currently when we check for the available resources, we assume that there
> is only one interconnect path, but in fact it could be more than one. Do
> some validation to determine the number of paths and verify if each one
> of them is available.
>
> Signed-off-by: Georgi Djakov <georgi.djakov@linaro.org>
> ---
> v8:
> * New patch.
>
> drivers/cpufreq/cpufreq-dt.c | 49 ++++++++++++++++++++++++++++++++----
> 1 file changed, 44 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/cpufreq/cpufreq-dt.c b/drivers/cpufreq/cpufreq-dt.c
> index 4ecef3257532..3dd28c2c1633 100644
> --- a/drivers/cpufreq/cpufreq-dt.c
> +++ b/drivers/cpufreq/cpufreq-dt.c
> @@ -91,12 +91,54 @@ static const char *find_supply_name(struct device *dev)
> return name;
> }
>
> +static int find_icc_paths(struct device *dev)
> +{
> + struct device_node *np;
> + struct icc_path **paths;
> + int i, count, num_paths;
> + int ret = 0;
> +
> + np = of_node_get(dev->of_node);
> + if (!np)
> + return 0;
> +
> + count = of_count_phandle_with_args(np, "interconnects",
> + "#interconnect-cells");
> + of_node_put(np);
> + if (count < 0)
> + return 0;
> +
> + /* two phandles when #interconnect-cells = <1> */
> + if (count % 2) {
> + dev_err(dev, "%s: Invalid interconnects values\n", __func__);
> + return -EINVAL;
> + }
> +
> + num_paths = count / 2;
> + paths = kcalloc(num_paths, sizeof(*paths), GFP_KERNEL);
> + if (!paths)
> + return -ENOMEM;
> +
> + for (i = 0; i < num_paths; i++) {
> + paths[i] = of_icc_get_by_index(dev, i);
> + ret = PTR_ERR_OR_ZERO(paths[i]);
> + if (ret)
> + break;
> + }
> +
> + while (i--)
> + icc_put(paths[i]);

Since the function only does a validation and throws the paths away
afterwards you don't really need the dynamic allocation and 'icc_put'
loop. Just have a single 'struct icc_path' pointer and call icc_put()
inside the for loop.